Photographic material as referred to herein is understood to be generally planar, may comprise film or paper, may produce a black-and-white or color image, and may be in a continuous web form or may comprise discrete sheets.
Silver halide photographic materials are well-known, and are processed to generate a silver or dye image via a development stage followed by a series of stages to stabilize and provide permanence to the image. The wash stages convert and remove unwanted materials from the coated photographic layers which would either interfere with the quality of the final image or cause degradation of the image with time. In typical color systems the development stage is followed by a bleach stage to oxidize the developed silver to a form which can be dissolved by a fixing agent in the same or a separate bath. Such silver removal stages are then followed by a washing stage using water, or other wash solution, or a stabilization stage using a stabilizer solution. Such stages remove residual chemicals and may also include conversion reactions between stabilizer solution components and materials within the coated layers. These stages are required to provide the required degree of permanence to the final image.
The various processing stages may comprise baths in which batches of the photographic material are immersed, but these can involve large quantities of solution that have to be replenished to maintain their efficiency, and the effluent subsequently has to be removed. It also known to carry out surface processing of photographic material in which a metered amount of processing solution is deposited onto a surface of the material, resulting in only a small amount being carried over by the material from one stage to the next, thus significantly reducing the amount of effluent. U.S. Pat. No. 5,752,121 discloses surface processing apparatus in which solution is applied in precise quantities to the sensitized side of photographic sheet film as it is conveyed on an endless belt beneath an applicator arrangement that comprises three rollers. The processing solution, for example developer, is metered onto an upper roller and is then transferred to the film as it is driven thereunder by the belt. The film is then passed through further processing stages.
In known surface processors, the photographic material to be processed is driven through at a constant speed, and this is so even though different drive rollers may be driven separately, since the material has to pass continuously from one stage, for example drive belt, to another. However, it may not be necessary for the material to spend the same time in each of the stages. Also, different materials may need to reside in a given stage for different times to effect the required processing.
It is one object of the present invention to provide a processing apparatus and method that is more versatile than that presently available in its ability conveniently to accommodate differing processing requirements.